1. Field of the Invention
The present invention relates to resin molding dies, in particular, to a resin molding die for embedding in a molded resin a bus bar unit for connecting an automotive lamp unit, such as a compartment lamp unit and a map lamp unit, to a power supply (battery) via switches.
2. Description of the Related Art
Hitherto, in an automotive lamp unit provided with compartment lamps, map lamps, and the like, a bus bar unit is mounted in grooves formed in a resin base member formed by an injection mold, and the lamps have been connected by the bus bar unit to a power source via switches.
The automotive lamp unit provided with a plurality of lamps, such as compartment lamps and map lamps, mounted in one base member must have a plurality of bus bars, the operation of mounting the bus bars on the base member being laborious. Moreover, a problem has been found in that the bus bars are likely to remove from the base member by vibration or the like because the bus bars are mounted on the base member only by being coupled therewith.
In order to overcome these problems, a technology disclosed in, for example, Japanese Unexamined Patent Application Publication No. 7-323784 may be used, in which a plurality of bus bars are integrated into one bus bar unit via bridge portions, and the bus bar unit is set in an injection mold and is embedded in a molded resin by injection.
The embedded bus bars are electrically separated from each other by being cut and separated from each other at the bridge portions by using a press machine or the like in the subsequent process. However, manufacturing costs significantly increase in this method because a blanking die is required and two processes are necessary, that is, an injection molding process and a process of cutting the bridge portions. Moreover, metallic particles-of the bridge portions are produced, which is waste in materials, and the metallic particles must be disposed of.
A method for overcoming these problems is known which uses a molding die disclosed in, for example, Japanese Unexamined Utility Model Application Publication No. 63-61129, in which a step of molding and a step of cutting bridge portions are simultaneously performed in a molding process. The configuration of the molding die is described below with reference to FIGS. 7A and 7B.
In FIGS. 7A and 7B, an injection mold 1 is provided with cutting blades 1a protruding therefrom for cutting a lead frame 3, and another injection mold 2 is provided with blade-receiving recesses 2a formed therein for receiving the cutting blades 1a. The molds 1 and 2 are provided with respective cavities 1b and 2b formed therein, in which a semiconductor chip 4 and a bonding wire 5 are embedded.
A method for molding by using molding dies having the above-described configuration is described below. The lead frame 3 is placed between the molds 1 and 2 so that the semiconductor chip 4 and the bonding wire 5 are positioned in the cavities 1b and 2b. 
When one of the molds 1 and 2, for example, the mold 1 comes close to the other mold, for example, the mold 2, the cutting blades 1a of the mold 1 cut away an unnecessary portion of the lead frame 3 and come into the blade-receiving recesses 2a, and the molds 1 and 2 cover the semiconductor chip 4 and the bonding wire 5 at the cavities 1b and 2b. 
After a melted resin is injected into the cavities 1b and 2b and is cured, a molded resin is discharged from the molds 1 and 2, whereby a product including the lead frame 3, from which the unnecessary portion is cut away, can be obtained.
In the above-described molds, particles 3a cut away by the cutting blades la remain in the blade-receiving recesses 2a. Therefore, a problem is found in that when the molding operation is repeatedly performed, the particles 3a are piled in the blade-receiving recesses 2a, of which removing operation is laborious.
In the known molds, the particles 3a are cut away by the cutting blades 1a by temporarily fixing the lead frame 3 to the mold 2. Therefore, when a load is applied to the lead frame 3, by the cutting blades 1a, the lead frame 3 removes from the mold 2, thereby producing a defective product in which the entire semiconductor chip 4 and the bonding wire 5 are not embedded in a molded resin.
Accordingly, it is an object of the present invention to provide a resin molding die for embedding in a molded resin a bus bar unit including a plurality of bus bars connected with each other via a bridge portion, in a manner such that the plurality of bus bars set in an injection mold are separated from each other at the bridge portion without cutting away the same, and a resin is injected into the injection mold. By using the resin mold, manufacturing processes can be reduced because a product can be manufactured in one process, and metallic particles are not produced because the bus bars are separated at the bridge portion without cutting away the same, whereby the consumption of a material is suppressed, a process of disposing of waste is omitted, and cut-away-particles are not necessary to be removed from the molding die.
It is another object of the present invention to provide a resin molding die for embedding in a molded resin a bus bar unit including a plurality of bus bars connected with each other via a bridge portion, in a manner such that the plurality of bus bars are separated from each other at the bridge portion by a pin fixed to a mold cutting and raising the bridge portion while the mold to which the pin is fixed is restraining the bus bar unit, whereby. the bus bar unit does not remove from the mold, thereby preventing defective products from being produced.
To these ends, according to an aspect of the present invention, a resin-molding die for embedding in a molded resin a plurality of bus bars connected with each other via a bridge portion comprises a supporting member formed on a first mold, for supporting the bus bars; a pin-receiving hole formed in the supporting member at a position associated with the bridge portion; and a pin provided on a second mold at the position associated with the bridge portion and the pin-receiving hole, for cutting and raising the bridge portion substantially at an intermediate part thereof.
The resin-molding die may further comprise a pressing member disposed at the second mold side for pressing the bridge portion at least in the vicinity of the bridge portion toward the supporting member. The pressing member may be formed on a movable member which is movable toward the second mold provided with the pin, the movable member being urged toward the first mold by a resilient member.
The second mold provided with the pin is preferably provided with a resin-conduit for supplying a melted resin into the resin-molding die, and the pin may cut and raise the bridge portion and the resin conduit may communicate with a chamber formed in the resin-molding die when the first mold presses the movable member toward the second mold against a resilient force of the resilient member.